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Promotion of Flowering in the Pinaceae by Gibberellins
Author(s) -
ROSS STEPHEN D.,
PHARIS RICHARD P.
Publication year - 1976
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1976.tb03932.x
Subject(s) - strobilus , gibberellin , girdling , pinaceae , botany , horticulture , douglas fir , biology , stamen , pinus <genus> , pollen
Flowering was significantly promoted in 4‐year‐old grafts of mature coastal Douglas‐fir ( Pseudotsuga menziesii (Mirb.) Franco) clones by exogenous gibberellins (GAs) A 4 and A 7 (as a mixture) applied alone and in combination with A 5 and A 9 . Biweekly applications of 400 μg GA 4/7 per branch between late March and late June gave a 5‐fold increase in ovulate and 3‐fold increase in staminate strobilus production over untreated controls. 6 N‐benzyladenine and 2,3,5‐triiodobenzoic acid applied in combination with GAs had no consistent effect on strobilus production. Non‐destructive branch girdling, ineffective by itself as a cultural treatment, enhanced the GA benefit to flowering. Exogenous application of GA 4/7 is effective and appears to be a practical method for promotion of early and enhanced flowering in grafted Douglas‐fir seed orchards.